/*
 * Copyright (c) 2014, marco.tamburelli@gmail.com
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met: 
 * 
 * 1. Redistributions of source code must retain the above copyright notice, this
 *    list of conditions and the following disclaimer. 
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution. 
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package org.omorphdb.core.test.mock.resource;

import static org.junit.Assert.assertEquals;

import java.io.IOException;
import java.util.concurrent.atomic.AtomicInteger;

import org.omorphdb.core.io.Appender;
import org.omorphdb.core.io.Reader;
import org.omorphdb.core.io.Resource;
import org.omorphdb.core.io.Writer;

/**
 * Mocks a resource; read write operation take place in a byte array of chosen
 * length.
 * 
 * @author Marco Tamburelli
 */
public class MockResource extends Resource
{
	private final byte[] array;
	private final AtomicInteger limit;

	/**
	 * Constructor.
	 * 
	 * @param length The size of the byte array where read and write.
	 */
	public MockResource(int length)
	{
		this.array = new byte[length];

		for (int i = 0; i < this.array.length; i++)
		{
			assertEquals(0, this.array[i]);
		}

		this.limit = new AtomicInteger();
	}

	@Override
	public Reader createReader() throws IOException
	{
		return new ByteArrayReader(this.array);
	}

	@Override
	public Writer createWriter() throws IOException
	{
		return new ByteArrayWriter(this.array);
	}

	@Override
	public Appender createAppender() throws IOException
	{
		return new ByteArrayAppender(this.array, this.limit.get())
		{
			@Override
			public void reserve(int length) throws IOException
			{
				setCursor(limit.getAndAdd(length));
			}
		};
	}

	@Override
	public long getResourceLimit()
	{
		return this.limit.longValue();
	}

	@Override
	public boolean remove() throws IOException
	{
		return false;
	}

}
